Efficient Sampling Procedures for Process Control in Non-Homogenous Product Mix Shops (with Extensions).

Abstract : The main problem was to develop a practical and theoretically sound sampling system, with its operating procedures, to establish effective control over the output of component rework shops in an aircraft maintenance and rework facility. The principal issue lay in the difference between process control and product acceptance. Also, because of the wide variation in time and procedures required for refurbish the components flowing through any given shop, a control statistic based on units rejected was virtually useless. Thus, a new control statistic, maintenance errors committed per 100 man-hours worked, was tested and found to follow relatively well the Poisson distribution within a given shop.